1. Field of the Invention
The present invention relates to double cylinder deadbolt locks and, more particularly, to an escutcheon assembly that allows virtually any shape of escutcheon to be secured to the inside cylinder of a double-cylinder deadbolt lock to match the outside face plate.
2. Description of the Background
A single-cylinder deadbolt lock typically provides a keyed-cylinder on the exterior of the door and a thumb-turn on the interior. Single-cylinder deadbolt locks can be easily opened from inside without a key, and manufacturers are unconcerned with tampering from the inside. Consequently, the interior and exterior face plates are typically attached by inserting screws through the interior face plate into threaded receptacles protruding rearwardly from the exterior face plate. This makes it impossible to remove the lock from the outside but quite easy from the inside. On the other hand, a double-cylinder deadbolt provides a keyed cylinder on both the interior/exterior. Thus, a key is needed even from the inside to unlock a double-cylinder deadbolt. In this case manufacturers are concerned with tampering from both sides, and no screws are accessible from either the interior or exterior face plates.
FIG. 1 illustrates a typical double-cylinder deadbolt lock assembly in which an outside cylinder 2 is seated in an outside cylinder housing 3. The outside cylinder 2 engages a deadbolt 5 that is anchored inside the door. On the inside of the door a removable-core inside cylinder 7 is inserted into an inside cylinder housing 6. The inside cylinder 7 is attached to the outside cylinder 2 by a pair of screws 8. A face plate 9 is seated atop the inside cylinder 7 to cover the screws 8, and the removable core 10 is inserted into the inside cylinder 7 and thereby captures the face plate 9 against the inside cylinder 7. A problem with the foregoing arrangement is that it does not allow for any interchangeability of face plates. Property owners often prefer square or other odd-shaped decorative face plates (other than round), and this is difficult with the illustrated configuration because the round cylinders must be seated in round face plates. There have been previous attempts to add decorative face plates or “escutcheons”. For example, U.S. Pat. No. 5,351,513 to Ellis issued Oct. 4, 1994 shows a double cylinder deadbolt provided with a cylinder housing collar 20 that fits around the inside cylinder. An escutcheon 80 is screwed onto collar 20 and substantially covers the lock, leaving the keyway accessible. Even here, due to the screw-attachment of the escutcheon 80 onto collar 20 both of these components are round.
It would be greatly advantageous to provide a secure mechanism for attachment of an escutcheon of any shape to a deadbolt lock, and particularly for attachment of an escutcheon to the interior side of a double-cylinder deadbolt lock to facilitate a match to the exterior face plate, no matter the shape. The new escutcheon assembly and attachment mechanism should be straightforward in manufacture and use.